Publications
Filter Total Items: 1990
Field response of tadpoles to conspecific and heterospecific alarm
Many organisms use chemical cues from a variety of sources to mediate predator avoidance. Response to heterospecific alarm cues has been demonstrated for tadpoles within but not among taxa and alarm response behavior has seldom been examined under field conditions. This study examined the response of three sympatric amphibian larvae and predaceous larval Dytiscus sp. (diving beetle) to damage-rele
Authors
M. J. Adams, S. Claeson
Vulnerability of desert biological soil crusts to wind erosion: The influences of crust development, soil texture, and disturbance
Biological soil crusts, consisting of cyanobacteria, green algae, lichens, and mosses, are important in stabilizing soils in semi-arid and arid lands. Integrity of these crusts is compromised by compressional disturbances such as foot, vehicle, or livestock traffic. Using a portable wind tunnel, we found threshold friction velocities (TFVs) of undisturbed crusts well above wind forces experienced
Authors
Jayne Belnap, Dale A. Gillette
Understory vegetation in old and young Douglas-fir forests of western Oregon
We studied understory composition in thinned and unthinned Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)/western hemlock (Tsuga heterophylla (Raf.) Sarg.) stands on 28 sites in western Oregon. These stands had regenerated naturally after timber harvest, 40–70 years before thinning. Commercial thinning had occurred 10–24 years previously, with 8–60% of the volume removed from below with the in
Authors
J. D. Bailey, C. Mayrsohn, P. S. Doescher, Elizabeth St. Pierre, J. C. Tappeiner
Routes and travel rates of migrating Peregrine Falcons Falco peregrinus and Swainson's Hawks Buteo swainsoni in the Western Hemisphere
We describe and compare the migration routes, length of migration, and duration of migration of Peregrine Falcons Falco peregrinus tundrius and Swainson's Hawks Buteo swainsoni in the Western Hemisphere. We radio tracked migrants using the Argos satellite system. Our initial samples were 34 Swainson's Hawks from representative areas of their breeding range, and 61 Peregrine Falcons captured at nes
Authors
Mark R. Fuller, William S. Seegar, Linda S. Schueck
Impact of alternative regeneration methods on genetic diversity in coastal Douglas-fir
Genetic implications of natural and artificial regeneration following three regeneration methods (group selection, shelterwood, and clearcut) were investigated in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) using genetic markers (17 allozyme loci). In general, harvesting followed by either natural or artificial regeneration resulted in offspring populations little alt
Authors
W.T. Adams, J. Zuo, J.Y. Shimizu, J. C. Tappeiner
Choosing indicators of natural resource condition: A case study in Arches National Park, Utah, USA
Heavy visitor use in many areas of the world have necessitated development of ways to assess visitation impacts. Arches National Park recently completed a Visitor Experience and Resource Protection (VERP) plan. Integral to this plan was developing a method to identify biological indicators that would both measure visitor impacts and response to management actions. The process used in Arches for in
Authors
J. Belnap
Influence of habitat on behavior of Towndsend's ground squirrels (Spermophilus townsendii)
Trade-offs between foraging and predator avoidance may affect an animal's survival and reproduction. These trade-offs may be influenced by differences in vegetative cover, especially if foraging profitability and predation risk differ among habitats. We examined above-ground activity of Townsend's ground squirrels (Spermophilus townsendii) in four habitats in the Snake River Birds of Prey National
Authors
Peter B. Sharpe, Beatrice Van Horne
The role of special angling regulations in management of coastal cutthroat trout
No abstract available.
Authors
Robert E. Gresswell, R.D. Harding
Surveying and monitoring amphibians using aquatic funnel traps
No abstract available.
Authors
M.J. Adams, K.O. Richter, W.P. Leonard
Silvicultural systems and regeneration methods: Current practices and new alternatives
No abstract available.
Authors
J. C. Tappeiner, D. Lavender, Robert O. Curtis, D.S. DeBell
Shaping stand development through silvicultural practices
No abstract available.
Authors
D.S. DeBell, Robert O. Curtis, C. Harrington, J. C. Tappeiner